The Criminal Investigation Agency under the Ministry of National Defence, in cooperation with military prosecutors, issued the decision on Tuesday, the Vietnam News Agency reported. Hien is now under house arrest.

The investigation is part of a fraud and land management case that saw former colonel Dinh Ngoc He sentenced to 12 years in jail in July last year.

Hien, 65, was retroactively dismissed as the Commander of Vietnam People's Navy per a decision by Prime Minister Nguyen Xuan Phuc last month for making "very serious" violations when he was the naval commander between 2004 and 2015.

For his wrongdoing, he had already been dismissed from all party positions in June.

The Communist Party of Vietnam has four modes of punishment against members: reprimand, warning, demotion and expulsion.

Hien, along with Vice Admiral Nguyen Van Tinh and Rear Admiral Le Van Dao, were responsible for several land management violations, said the Central Inspection Committee, the party's top watchdog.

The violations resulted in major financial losses and badly affected the reputation of the Communist Party and the People's Navy, the committee said.

In April, the committee had concluded that the Standing Committee of the People's Navy's party unit had committed several serious violations. It had violated the principle of democratic centralism, broken working regulations, and been negligent in leading, managing, inspecting and supervising, resulting in violations on using national defense land, the committee said.

A sweeping corruption crackdown spearheaded by party chief and President Nguyen Phu Trong has snared scores of high-profile officials over the last three years.